Internal combustion engine



R. E. OLDS 2,230,308

INTERNAL COMBUSTION ENGINE Feb. 4, 1941.

Filed Jan.

INVENTOR. Y RANSOMIEDLDS zfmw WW ATTORNEYS Patented Feb. 4, 1941 UNITEDSTATES PATENT tries 3 Claims.

The invention relates to multi-cylinder internal combustion engines ofthe two-cycle fuel injection type. It is the object of the invention toobtain a construction which provides, first for thoroughly scavengingthe cylinders from exhaust gases, and second for supercharging the same.To this end, the invention consists in the construction as hereinafterset forth.

The drawing which is partly diagrammatic,

1 illustrates a central longitudinal section through the severalcylinders of the engine and their connections.

As illustrated, I, 2 and 3 are cylinders of a multi-cylinder engine.Each cylinder has a small diameter portion A and a larger diameterportion B, the former being used as a power cylinder and the latter forcompression of air. C is a piston having a portion C for engaging thecylinder A and a portion C engaging the cylinder B. Each piston isconnected by a rod D with a crank E on the crank shaft F, and where thenumber of cylinders is three, the angle between cranks is 120.

The several cylinders may be arranged in any desired relation to eachother, and if desired may be formed in an integral block. However, Ihave diagrammatically represented the cylinders as separate and arrangedin rectilinear alignment. The cylinder portion B of cylinder l is con- 3nected by a conduit G with cylinder portion A of cylinder 2. Thecylinder portion B of cylinder 2 is connected by a conduit H with thecylinder portion A of cylinder 3, and the cylinder portion B of cylinder3 is connected by a conduit I with the cylinder portion A of cylinder I,thereby forming an endless series. These several air conduitscommunicate with the cylinders A through ports including a scavengingair admission port J located adjacent to the end of the power stroke ofthe piston and controlled solely by said piston. A second superchargingport K is located at an intermediate point in the stroke of the pistonand is controlled by a valve L in a valve casing L, which is closedduring the power stroke by a spring L but is opened during thecompression stroke subsequent to the scavenging of the cylinder. Theexhaust port M is arranged on the opposite side of the cylinder from theports J and K, and is located to be uncovered by the piston slightly inadvance of the opening of th scavenging port J.

Air is admitted to each of the air compression cylinders B from amanifold N, which communicates through a port 0 with a chamber P, andthe latter through a port Q with the cylinder B.

A check valve R controls the port 0, closing during the compressionstroke of the large piston 0 A port S delivers the compressed air fromthe cylinder B into the conduit G.

With the construction as described, the operation is as follows.Assuming that the piston in the portion A of cylinder l is in the earlypart of its power stroke, then the piston in the portion A of cylinder 2is in its compression stroke, and the piston in the portion A ofcylinder 3 is in scavenging position. In the latter cylinder, airpreviously compressed by the piston C in cylinder 2, passes through theconduit H and through the scavenging port J to sweep the exhaust gasesfrom the cylinder out through the exhaust port M. The valve L will alsobe opened against the tension of the spring L by the more thanatmospheric pressure in the conduit H, and as soon as the piston hasclosed the exhaust port M, a supercharge of air will be introduced intothe cylinder portion A (due to an accumulated pressure in H) andcompressed by the continuing upward stroke of the piston. The largepiston C in the portion B of cylinder 3 has just completed its suctionstroke, air having been drawn in from the manifold N, past the valve R,and through the port Q. This will be compressed during the upward strokeof the piston and conveyed through the conduit I to cylinder l ready foruse in scavenging and supercharging. In cylinder I fuel has beenadmitted through the nozzle T (this forming no part of the instantinvention), and as before stated, the piston C is in the early part ofthe power stroke. The large piston C in portion B of cylinder I is atthe beginning of its suction stroke and the valve R is opened foradmission of air. In cylinder 2 compression is taking place in both thelarge diameter portion B and small diameter portion A.

From the description above given, it is believed that the successivephases of the cycle in each cylinder will be understood, the efiectbeing to thoroughly scavenge the exhaust gases from each cylinder and tothen introduce a supercharge. The construction is simple, avoiding thenecessity of a separate supercharger and doing away with cam shaftgears, cam shafts, and cams. All of the cylinder units are the same inconstruction and, may be assembled in any desired relation to eachother.

What I claim as my invention is:

1. In an internal combustion engine of the twocycle fuel injection type,a series of stepped cylinders and cooperating pistons each having asmall diameter power portion and a large diameter air compressionportion, the latter displacing a measured volume of air, a conduitconnecting the air compression portion of each cylinder with the powerportion of another cylinder in endless series, each of said conduitscommunicating with the power cylinder through a piston controlledscavenging port located adjacent to the end of the power stroke of thepiston and also through a separate valve controlled supercharging portlocated at an intermediate point in the stroke of the piston there beingalso an exhaust port in each power cylinder located intermediate saidair inlet ports whereby a definite portion of the measured volume of airdisplaced in each air compression cylinder is utilized for superchargingthe next cylinder in the series.

2. In an internal combustion engine of the twocycle fuel injection type,a series of stepped cylinders and cooperating pistons each having asmall diameter power portion and a large diameter air compressionportion, the latter displacing a measured volume of air, a conduitconnecting the air compression portion of each cylinder with the powerportion of another cylinder in endless series, each of said conduitscommunicating with the power cylinder through a piston controlledscavenging port located adjacent to the end of the power stroke of thepiston and also through a separate supercharging port located at anintermediate point in the stroke of the piston there being an exhaustport in each power cylinder located intermediate said air inlet portsand on the opposite side of the cylinder, and a valve controlling saidsupercharging port closed during the power stroke of the piston andopened when the air pressure within said conduit exceeds that in thecylinder whereby a definite portion of the measured volume of airdisplaced in each air compression cylinder is utilized for superchargingthe next cylinder in the series.

3. In an internal combustion engine of the twocycle fuel injection type,a series of stepped cylinders and cooperating pistons each having asmall diameter power portion and a large diameter air compressionportion, the latter displacing a measured volume of air, a conduitconnecting the air compression portion of each cylinder with the powerportion of another cylinder in endless series, each of said conduitscommunicating with the power cylinder through a piston controlledscavenging port located adjacent to the end of the power stroke of thepiston and also through a separate supercharging port located at anintermediate point in the stroke of the piston there being also anexhaust port in each power cylinder located intermediate said air inletports and upon the opposite side of the cylinder, and an automatic valvecontrolling said supercharging port closed by pressure within thecylinder in excess of pressure within the conduit and open by excess ofair pressure in the conduit over that in the cylinder whereby a definiteportion of the measured volume of air displaced in each air compressioncylinder is utilized for supercharging the next cylinder in the series.

RANSOM. E. OLDS.

